1. Field of the Invention
The invention concerns flowable cleanser compositions formulated with high levels of fatty acid salt (soap).
2. The Related Art
Modern products need to be more environmentally friendly. They must be engineered to have lower energy consumption, utilize sustainable resources (i.e. avoid fossil fuels) and conserve water resources. In personal cleansing products, this means rethinking toilet bar and liquid hand and body wash formulations. Toilet bars have the beneficial aspect of delivering surfactant as a concentrate; they usually contain more than 50% surfactant. Unfortunately, bars are slow to lather. Considerable running water is wasted to initiate lather. A second disadvantage is the impossibility for a consumer to measure out a precise dose of cleansing composition from a bar format. Too much material is consequently washed down the drain.
These disadvantages are overcome through use of liquid hand wash and body wash (shower gel) products. These can be accurately dosed and they lather relatively more quickly. Unfortunately, this format requires incorporation of relatively high amounts of water within the formulations. This results in necessity for larger packaging, a significant portion of which is merely to transport sometimes 50% or more water. There are also incremental wastes of energy in transporting a largely water based system.
Environmental and sustainability problems with personal cleansers can be overcome through use of flowable low water content concentrates. These contain relatively high levels of surfactant but utilize only enough water to allow quick initial lathering and controlled dosing.
Soaps are fatty acid salts. The fatty acids are sustainably sourceable from palm oil and other vegetative raw materials. In our work formulating high levels of soap, the present inventors have obtained resultant concentrates prone to partial crystallization of the soap. Even small amounts of crystallization resulted in visually displeasing products. Ordinarily clear compositions turned turbid. Also there were problems with maintaining an even viscosity. Accordingly, soap based concentrates were sought that have good stability against crystallization.